A peer-reviewed study conducted by the Johns Hopkins Bloomberg School of Public Health and the University of North Carolina at Chapel Hill has found that some farm workers carry antibiotic-resistant bacteria in their noses. Other authors included scientists from the Rural Empowerment Association for Community Help and George Washington University. This study confirms earlier findings. The resistant bacteria were twice as common among workers in the industry that used antibiotics on animals.

Dr. Christopher Heaney, corresponding author of the study said in a statement, “this study shows that these livestock-associated strains are present among workers at industrial livestock operations and that these strains are resistant not just to methicillin, but to multiple antibiotics – including antibiotics that are used to treat human infections.” Workers at operations that carried antibiotic-free livestock did not harbor the resistant bacteria. The workers were not sick at the time of the study.

The bacteria was Staphylococcus aureus. New strains of this bacteria are emerging in people who are in close contact with livestock. Only industrial workers carried the antibiotic-resistant bacteria with multiple genetic markers that linked the bacteria to the livestock. S. aureus includes the dangerous bacteria MRSA (methicillin-resistant Staphylococcus aureus).

The study concludes by stating “these findings support growing concern about antibiotic use and confinement in livestock production, raisins questions about the potential for occupational exposure to an opportunistic and drug-resistant pathogen, which in other settings including hospitals and the community is of broad public health importance.” The sub therapeutic use of antibiotics in farm animals has been addressed by members of Congress, food safety experts, and members of the medical community.